Instantaneous Status To Target Gauge For Vehicle Application

ABSTRACT

A vehicle includes a display and a controller that operates the display. A first icon representing a reference energy consumption value based on a predetermined target energy consumption rate is displayed. A second icon representing a present energy consumption value is displayed. The icons are positioned relative to one another based on a difference between the reference energy consumption value and the present energy consumption value. A numerical scale may be displayed having values associated with the first and second icons. A vehicle having a hybrid powertrain including a traction battery may display an effective electric distance traveled that is based on a ratio of power supplied by the traction battery to total power supplied by the powertrain.

TECHNICAL FIELD

This application is generally related to vehicle gauges and displays forenergy consumption of a vehicle.

BACKGROUND

A vehicle display provides information and feedback to the operatorregarding operation of the vehicle. For example, in vehicles includingan internal combustion engine, a fuel gauge indicates an amount of fuelremaining in a fuel tank. This provides valuable information to anoperator to indicate when more fuel should be added to the fuel tank.Other information, such as average fuel economy or instantaneous fueleconomy, may also be displayed.

An information display unit for a vehicle that includes a tractionbattery and an electric machine may display information regarding thestate of a traction battery. Information such as battery state of chargeand a distance until zero state of charge may be displayed. A displayunit for a hybrid-electric vehicle that includes an engine may displayinformation related to the engine along with information related to thetraction battery.

SUMMARY

A vehicle includes a display and at least one controller. The controlleris programmed to operate the display according to a reference energyconsumption value based on a predetermined target energy consumptionrate and a present energy consumption value such that a position of afirst icon relative to a position of a second icon is based on adifference between the reference energy consumption value and thepresent energy consumption value. The controller may be furtherprogrammed to display a first numerical value associated with the firsticon and a second numerical value associated with the second icon,wherein the first numerical value corresponds to the reference energyconsumption value and the second numerical value corresponds to thepresent energy consumption value. The present energy consumption valuemay be based on a time averaged energy consumption rate. The presentenergy consumption value may be based on a distance averaged energyconsumption rate. The present energy consumption value may be based on adistance traveled during an ignition cycle. The present energyconsumption value may be based on a present amount of energy remainingin a traction battery. The present energy consumption may be based on anamount of energy that a traction battery is capable of storing at fullcharge. The present energy consumption value may be a distance remainingto fully discharge a traction battery. The present energy consumptionvalue may be a predicted distance traveled if a traction battery isfully charged and energy is used at a present actual energy consumptionrate. The present energy consumption value may be based on a ratio ofpower supplied by a traction battery to total power supplied by thevehicle

A method for displaying vehicle energy consumption on a display includesdisplaying a first icon associated with a reference energy consumptionvalue based on a predetermined target energy consumption rate. Themethod also includes displaying, at a position relative to the firsticon by a distance that is based on a difference between a presentenergy consumption value and the reference energy consumption value, asecond icon associated with the present energy consumption value. Themethod may further comprise displaying a first numerical valueassociated with the first icon and a second numerical value associatedwith the second icon, wherein the first numerical value corresponds tothe reference energy consumption value and the second numerical valuecorresponds to the present energy consumption value. The method mayfurther comprise displaying a scale corresponding to a range of valuesfor energy consumption, wherein the first icon is positioned adjacentthe scale at a position corresponding to the reference energyconsumption value and the second icon is positioned adjacent the scaleat a position corresponding to the present energy consumption value. Thepresent energy consumption value may be based on a ratio of powersupplied by a traction battery to total power supplied by a vehicle. Thepresent energy consumption value may be based on a distance averagedenergy consumption rate. The present energy consumption value may be adistance remaining to fully discharge a traction battery. The presentenergy consumption value may be a predicted distance traveled if atraction battery is fully charged and energy is used at a present actualenergy consumption rate.

A vehicle includes a powertrain including a traction battery, a display,and at least one controller programmed to operate the display toindicate an effective electric distance traveled that is based on aratio of power supplied by the traction battery to total power suppliedby the powertrain. The powertrain may include an internal combustionengine and total power supplied by the powertrain may include powersupplied by the internal combustion engine. The at least one controllermay be further programmed to operate the display to indicate a referenceelectric distance traveled that is based on a predetermined targetenergy consumption rate. The at least one controller may be furtherprogrammed to operate the display such that a position of a first icon,representing the effective electric distance traveled, relative to aposition of a second icon, representing the reference electric distancetraveled, is based on a difference between the reference electricdistance traveled and the effective electric distance traveled.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a hybrid vehicle illustrating typical drivetrainand energy storage components.

FIG. 2 is a diagram of an information display system within a vehicle.

FIG. 3 is a flowchart depicting possible operations for displayingenergy consumption values.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to beunderstood, however, that the disclosed embodiments are merely examplesand other embodiments can take various and alternative forms. Thefigures are not necessarily to scale; some features could be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the presentinvention. As those of ordinary skill in the art will understand,various features illustrated and described with reference to any one ofthe figures can be combined with features illustrated in one or moreother figures to produce embodiments that are not explicitly illustratedor described. The combinations of features illustrated providerepresentative embodiments for typical applications. Variouscombinations and modifications of the features consistent with theteachings of this disclosure, however, could be desired for particularapplications or implementations.

FIG. 1 depicts a typical plug-in hybrid-electric vehicle (PHEV). Atypical plug-in hybrid-electric vehicle 12 may comprise one or moreelectric machines 14 mechanically connected to a hybrid transmission 16.The electric machines 14 may be capable of operating as a motor or agenerator. In addition, the hybrid transmission 16 is mechanicallyconnected to an engine 18. The hybrid transmission 16 is alsomechanically connected to a drive shaft 20 that is mechanicallyconnected to the wheels 22. The electric machines 14 can providepropulsion and deceleration capability when the engine 18 is turned onor off. The electric machines 14 also act as generators and can providefuel economy benefits by recovering energy that would normally be lostas heat in the friction braking system. The electric machines 14 mayalso reduce vehicle emissions by allowing the engine 18 to operate atmore efficient speeds and allowing the hybrid-electric vehicle 12 to beoperated in electric mode with the engine 18 off under certainconditions.

A traction battery or battery pack 24 stores energy that can be used bythe electric machines 14. A vehicle battery pack 24 typically provides ahigh voltage DC output. The traction battery 24 is electricallyconnected to one or more power electronics modules. One or morecontactors (not shown) may isolate the traction battery 24 from othercomponents when opened and connect the traction battery 24 to othercomponents when closed. The power electronics module 26 is alsoelectrically connected to the electric machines 14 and provides theability to bi-directionally transfer energy between the traction battery24 and the electric machines 14. For example, a typical traction battery24 may provide a DC voltage while the electric machines 14 may require athree-phase AC current to function. The power electronics module 26 mayconvert the DC voltage to a three-phase AC current as required by theelectric machines 14. In a regenerative mode, the power electronicsmodule 26 may convert the three-phase AC current from the electricmachines 14 acting as generators to the DC voltage required by thetraction battery 24. The description herein is equally applicable to apure electric vehicle. For a pure electric vehicle, the hybridtransmission 16 may be a gear box connected to an electric machine 14and the engine 18 may not be present.

In addition to providing energy for propulsion, the traction battery 24may provide energy for other vehicle electrical systems. A typicalsystem may include a DC/DC converter module 28 that converts the highvoltage DC output of the traction battery 24 to a low voltage DC supplythat is compatible with other vehicle loads. Other high-voltage loads,such as compressors and electric heaters, may be connected directly tothe high-voltage without the use of a DC/DC converter module 28. Thelow-voltage systems may be electrically connected to an auxiliarybattery 30 (e.g., 12V battery).

The vehicle 12 may be an electric vehicle or a plug-in hybrid vehicle inwhich the traction battery 24 may be recharged by an external powersource 36. The external power source 36 may be a connection to anelectrical outlet. The external power source 36 may be electricallyconnected to electric vehicle supply equipment (EVSE) 38. The EVSE 38may provide circuitry and controls to regulate and manage the transferof energy between the power source 36 and the vehicle 12. The externalpower source 36 may provide DC or AC electric power to the EVSE 38. TheEVSE 38 may have a charge connector 40 for plugging into a charge port34 of the vehicle 12. The charge port 34 may be any type of portconfigured to transfer power from the EVSE 38 to the vehicle 12. Thecharge port 34 may be electrically connected to a charger or on-boardpower conversion module 32. The power conversion module 32 may conditionthe power supplied from the EVSE 38 to provide the proper voltage andcurrent levels to the traction battery 24. The power conversion module32 may interface with the EVSE 38 to coordinate the delivery of power tothe vehicle 12. The EVSE connector 40 may have pins that mate withcorresponding recesses of the charge port 34. Alternatively, variouscomponents described as being electrically connected may transfer powerusing a wireless inductive coupling.

The various components discussed may have one or more associatedcontrollers to control and monitor the operation of the components. Thecontrollers may communicate via a serial bus (e.g., Controller AreaNetwork (CAN)) or via discrete conductors. In addition, a systemcontroller 48 may be present to coordinate the operation of the variouscomponents.

FIG. 2 depicts an information display system 100 that may be included inthe vehicle 12 for providing feedback to an operator. The informationdisplay system 100 may include a display 102 located in a dashboard ofthe vehicle 12 in a convenient position for viewing by the operator. Theinformation display system 100 may include an associated displaycontroller 104 that controls and operates the display 102 via a discreteor serial interface 108. The display controller 104 may interface withone or more other vehicle controllers to receive data to be displayedover a communications link. An operator controls interface 116 may beincluded and may include one or more buttons or switches 118. Theoperator controls interface 116 may communicate with the displaycontroller 104 via a serial or discrete interface 120.

Conventional vehicles driven with an internal combustion engine displaya fuel level indication. The fuel level indication provides feedback tothe operator as to the amount of fuel remaining. Such an indicationhelps to ensure that the operator does not deplete the remaining fuel atan unexpected location. With the introduction of hybrid and electricvehicles, drivers may desire more feedback regarding efficiency andenergy consumption. It is desirable to provide feedback to the operatorto help achieve efficiency and energy consumption goals of the operator.

Typical feedback also includes an odometer reading that indicates thetotal distance traveled by the vehicle 12. In addition, one or moreresettable trip odometers may be present to indicate the distancetraveled for a particular trip. The trip odometers generally count upthe distance traveled from zero after a reset. The operator may initiatethe reset by operating a switch or button 118. The odometer and tripodometers may provide signals to the display controller 104.

An electric vehicle depends solely on the traction battery 24 to provideenergy for propulsion. Information regarding the amount of energy storedin the traction battery 24 and an expected range of the vehicle 12 maybe desired by the operator. The expected range may be a distance toempty (DTE) indication which is a distance that the vehicle 12 may beexpected to travel based on a present state of charge of the tractionbattery 24.

The vehicle 12 may display information regarding fuel economy. Anindication of instantaneous fuel economy may be displayed. Theinstantaneous fuel economy may be in units of miles per gallon and maybe calculated over a predetermined time period. An average fuel economymay be displayed that indicates the vehicle fuel economy over a longerperiod of time. The average fuel economy may be resettable.

A vehicle buyer may purchase a hybrid or electric vehicle based on fueland energy efficiency. The buyer or of these vehicles may preferfeedback that may help them drive in a more energy efficient manner. Forexample, displays of instantaneous fuel economy may help the operator toadjust operation of the vehicle based on the displayed feedback. For anelectric vehicle, the display may include remaining range that is adistance until the battery is fully discharged. The display may alsoinclude an instantaneous energy consumption value.

The display 102 may be a Liquid Crystal Display (LCD) screen having anumber of pixels. The display 102 may be capable of displaying inmonochrome or in color. The display 102 may not be limited to displayingnumerical quantities, but may display graphical figures as well. Adisplayed quantity may be associated with a graphical figure or icon tobetter convey what the information relates to.

The information display system 100 may be configured to displayinformation related to vehicle performance measures. Displayedinformation may include various fuel and energy consumption measures.The display 102 may be operated to display a numerical valuecorresponding to the vehicle performance measures in digital form and/orindicate the value on a scale or range of values. A classic example of avehicle performance measure display may be a speedometer which indicatesthe vehicle speed. A needle may point to a value on a gauge to indicatethe present value of the performance measure (e.g., vehicle speed).

Although the present value of the vehicle performance measure is usefulinformation, an operator may desire to compare the performance relativeto a target value. For example, when a vehicle 12 is manufactured forsale, a window label or sticker is applied to indicate importantinformation about the vehicle. Governmental agency regulations (e.g.,U.S. Environmental Protection Agency (EPA)) may require that certaininformation be listed on the window label. Information on the windowlabel may include fuel and energy consumption ratings. For example,vehicles including a gasoline engine list city and highway fuel economyvalues in miles per gallon (mpg) on the label. Plug-in hybrid andelectric vehicles list an energy consumption rate in kilowatt-hours per100 miles (kW-hr/100 mi) and a driving range that is the distance thevehicle can travel on a full battery charge. Such information givesvehicle buyers useful information for comparing the performance ofdifferent vehicles.

In addition, vehicle manufacturers may advertise the vehicle 12 usingvarious consumption ratings or targets. The operator may desire to knowhow the vehicle 12 is performing relative to these advertised or labelratings. The information display system 100 may be configured to displaya target or reference value along with the actual performance measure.This may allow the operator to readily compare the present vehicleperformance to the target value. Additionally, displaying a referencevalue provides a target for the operator to achieve or surpass.

A variety of energy consumption measures may be displayed. The energyconsumption values displayed may provide information related to energyconsumption of the vehicle. The displayed values may be indicative ofhow energy is being consumed and how much energy remains to be used. Theenergy consumption values displayed may include a rate of energyconsumption and an amount of energy consumed. An energy consumption ratemay be an energy consumption that is time averaged or distance averaged(dependent upon the consumption target). The time or distance over whichthe energy consumption is averaged may be a calibrateable value. Forexample, the energy consumption rate may be the actual energyconsumption over a distance in units of Wh/km. The actual energyconsumption rate may be displayed along with a reference value that isthe rated energy consumption rate from the label. A trip basedcomparison of the actual energy consumption rate (Wh/km) may bedisplayed in which a new trip is initiated at each ignition cycle. Theactual and rated energy consumption rates for the present trip orignition cycle may be displayed.

A scale 114 may be displayed with a range of selected energy consumptionvalues. The actual energy consumption value and the rated energyconsumption value may be displayed on or adjacent the scale 114. Thedisplayed scale 114 may be a portion of a complete range of possiblevalues. The displayed scale values 114 may change as the actual andrated energy consumption values change over time.

The energy consumption value displayed may be an estimate of remainingelectric range. This may be referred to as a distance to empty (DTE)estimate. The rated energy consumption value may be a range remainingthat is based on the rated energy consumption rate from the label. Theremaining electric range may be calculated based on an amount of energyremaining in the traction battery and a present energy usage rate. Thepresent energy usage rate may be an average energy usage rate over apredetermined time period. The DTE estimate value may be averaged in thetime or distance domains. The time or distance over which the energyconsumption value is averaged may be calibrateable.

The energy consumption value displayed may be a range per full charge(RPFC) estimate. The rated energy consumption value may be a range perfull charge value from the label. A trip based energy consumption valueof range per full charge may be used in which a new trip is initiated ateach ignition cycle. The RPFC may be based on a present energyconsumption rate.

The energy consumption value displayed may be an actual distancetraveled. The distance traveled may be defined over a single trip, anignition cycle, or some predetermined starting point. The rated energyconsumption value may be a reference distance traveled that is based onthe rated energy consumption rate from the label.

The energy consumption values to be displayed may be based on the totalenergy consumption of the vehicle 12. A number, N, of factors or systemsthat consume energy may be present on the vehicle 12. The total energyconsumption may be determined by monitoring the energy consumption ofeach of the individual energy consumers, such as the electric machines14 and the DC/DC converter module 28, and summing the results. Theenergy consumption rate of the vehicle 12 may be determined using thetotal energy consumption and the time or distance. The distance may bepredicted or estimated.

Energy consumption values may be time averaged. An average powerconsumption value (in Watts) for the vehicle 12 may be calculated. Theaverage power may be calculated as:

p _(i,avg)(k)=(1−α)p _(i,avg)(k−1)+α*p _(i)(k)

where p_(i,avg) is the average power consumed for the i^(th) factor (inWatts), p_(i) is the instantaneous power consumed for i^(th) factor (inWatts), k is a discrete time index, and a is a filter constant. Theaverage power may be determined for each of the N factors. Theinstantaneous power consumed by an electrical load may be computed as aproduct of a voltage and a current. The filter constant determines howquickly the average power value responds to changes in the instantaneouspower consumed. Alternatively, the average power may be calculated bysumming N power values and dividing the sum by N. An average vehiclespeed (in kph) may be determined in a similar manner.

A time averaged energy consumption rate for the different factors (inWatt-hours per kilometer) may be calculated as:

r _(i,avg,time) =p _(i,avg) /v _(avg)

where r_(i,avg) is the average energy consumption rate due to the i^(th)factor (Whr/km) and v_(avg) is the average vehicle speed (km/hr).

The total vehicle energy consumption rate may be calculated as the sumof the average energy consumption rate due to each of the systemsconsidered as follows:

$r_{{total},{time}} = {\sum\limits_{1}^{N}r_{i,{avg},{time}}}$

The total energy consumption may be determined as the product of thetotal vehicle energy consumption rate and the distance traveled.

The energy consumption values may also be determined on a per trip basisor averaged over distance. The cumulative energy consumed may berecorded over the trip and a distance traveled for the current trip maybe calculated. The cumulative energy consumed may be expressed as:

e _(i,trip)(k)=e _(i,trip)(k−1)+Δt*p _(i)(k)

where e_(i,trip) is the energy consumed during the current trip for thei^(th) factor (Whr) and Δt is the calculation loop time (hr). A typicalcalculation loop time may be 100 milliseconds. The total energyconsumption may be obtained by summing the energy consumed by each ofthe factors. The distance of the current trip may be calculated as:

d _(trip)(k)=d _(trip)(k−1)+Δt*v(k)

where d_(trip) is the trip distance (km) and v is the vehicle speed(km/hr).

The distance averaged energy consumption rate for the i^(th) factor maybe calculated as:

r _(i,avg,trip) =e _(i,trip) /d _(trip)

The distance averaged total vehicle energy consumption rate may becalculated as the sum of the distance averaged energy consumption ratesfor each of the factors considered as follows:

$r_{{total},{trip}} = {\sum\limits_{1}^{N}r_{i,{avg},{trip}}}$

The per trip energy consumption may be reset by setting thee_(i,trip)(k−1) values to zero. This may be performed at each ignitioncycle or may be performed by operator action (e.g., switch or buttonoperation). The average or instantaneous energy consumption rate may bedisplayed along with the target energy consumption rate from the vehiclelabel. The controller 104 may store the trip based energy consumptionrate values in non-volatile memory for later display and comparison.

An expected DTE based on the present amount of energy stored in thetraction battery may be computed and displayed. The expected DTE may becalculated based on the average total energy consumption rate as:

DTE_(e) =E _(batt) /r _(total,x)

where DTE_(e) is the predicted electric distance to empty (km), E_(batt)is the present energy available (Whr) from the traction battery andr_(total,x) is the energy consumption rate averaged over time ordistance. The expected DTE based on a reference energy consumption ratemay be calculated as

DTE_(e,ref) =E _(batt) /r _(avg,ref)

where DTE_(e,ref) is the predicted reference distance to empty (km) andr_(avg,ref) is a reference average energy consumption rate (Whr/km). Thereference average energy consumption rate may be derived from the windowlabel. For example, an EPA window label for an electric vehicle mayprovide an estimate of the energy consumption rate in kW-hrs/100 miwhich may be converted to Whr/km. This EPA window label energyconsumption rate may be used as the target energy consumption rate.

The DTE based on the present amount of energy stored in the tractionbattery yields a value that decreases as the battery energy is used. Thebehavior is similar to that of a fuel gauge. Over time, this value maycount down toward zero. Both the instantaneous value and the referencevalue may decrease toward zero over time.

An expected DTE based on a fully charged traction battery (also referredto as RPFC) may also be computed. An expected DTE for the fully chargedbattery may be calculated based on the average total energy consumptionrate as:

DTE_(e, fullcharge) =E _(batt,fullcharge) /r _(total,x)

where DTE_(e,fullcharge) is the predicted electric range for a fullycharged battery (km) and E_(batt,fullcharge) is the energy stored in afully charged battery (Whr). The expected distance of a fully chargedbattery based on a reference energy consumption rate may be calculatedas:

DTE_(e,ref,fullcharge) =E _(batt,fullcharge) /r _(avg,ref)

where DTE_(e,ref,fullcharge) is the predicted reference electric rangefor a fully charged battery (km), r_(avg,ref) is the reference averageenergy consumption rate (Whr/km). Alternatively, the reference value maybe the EPA label value for estimated distance traveled on a full charge.

The DTE based on a full battery charge yields a value that may remainwithin a range over time based on the present energy usage from thebattery. The reference value may remain constant over time with thepresent value changing relative to the reference. The display mayindicate an operator's performance relative to the target distance.

The information display system 100 may display the target and presentenergy consumption values in the form of a distance traveled race. Adistance prediction for the vehicle 12 operating with the actual energyconsumption rate may be compared to a reference vehicle operating with areference energy consumption rate. The reference energy consumption ratemay be determined as a target value corresponding to the vehicle label.The distance predictions may count down toward zero to indicate anexpected distance remaining. Alternatively, the distances may be countedup to indicate a total distance traveled. The distance of the referencemay indicate a distance that would have been traveled if the trip energywere consumed at the reference energy consumption rate.

An effective electric distance traveled or electric only DTE estimatemay also be computed for a hybrid-electric vehicle. The fractionalenergy derived from the battery may be calculated as:

E _(fraction) =p _(elec)(p _(elec) +c _(fuel)*η_(comb) *q _(fuel))

where E_(fraction) is the fraction of energy from the battery, p_(elec)is the electric battery power (W), c_(fuel) is the fuel energy density(J/L), η_(comb) is the combustion efficiency and q_(fuel) is thevolumetric flow rate (L/s). Note that for an electric only vehicle theE_(fraction) is one since all energy is provided by the tractionbattery. Other examples may include a fuel cell vehicle in which thedenominator is modified to reflect the energy provided by the fuel cellsource.

An effective electric distance traveled for the trip may be recorded as:

d _(elec,trip)(k)=d _(elec,trip)(k−1)+Δt*v(k)*E _(fraction)(k)

where d_(elec,trip) is the effective trip electric distance traveled(km).

The cumulative electric energy consumed is:

e _(elec,trip)(k)=e _(elec,trip)(k−1)+Δt*p _(elec)(k)

where e_(elec,trip) is the electric energy consumed for the trip (Whr).The reference electric distance traveled is:

d _(elec,ref) =e _(elec,trip) /r _(avg,ref)

The effective electric distance traveled provides an indication of theamount of the energy that is provided from the traction battery. Thereference electric distance traveled indicates the electric distancethat would be expected based on the label or rated consumption rate. Anoperator may compare the effective and reference electric distances toevaluate the performance.

The display 102 may be operated to indicate the vehicle performancemeasure in relation to a calibrateable target value for the vehicleperformance measure. For example, actual energy consumption and thelabel energy consumption may be displayed. The label energy consumptionmay be an energy consumption depicted on a label that containsinformation about the vehicle prior to sale. The label energyconsumption may be considered to be the target value. A graphicalrepresentation of consumption may be displayed compared to the targetvalue.

A graphical representation may be provided to display the actual andtarget quantities. One representation may be to display the values alongwith an icon or graphical depiction of an automobile. A scale 114 havingappropriate values for the energy consumption quantities to be displayedmay be positioned on the display 102. For example, in a DTE mode, thescale 114 may display numbers representing miles or kilometers thatremain until the battery is depleted. A first automobile icon 110 mayrepresent the target or rated value. The first automobile icon 110 mayhave a value associated with it that is the target value displayed as anumerical number. A second automobile icon 112 may represent the actualor present value of the performance measure. The second automobile icon112 may have a value associated with it that is the present value of theperformance measure (e.g., DTE). The first automobile icon 110 mayremain in a fixed location on the display 102. The position of thesecond automobile icon 112 relative to the first automobile icon 110 mayvary as the actual value of the performance measure changes. Therelative position of the second automobile icon 112 to the firstautomobile icon 110 may be based on the difference between the targetvalue and the present value of the performance measure.

Such a graphical representation may resemble a “chase” on the display.The second automobile icon 112 may appear to move in relation to thefirst automobile icon 110. The driver is provided with feedbackregarding the present driving performance. The driver may change theirdriving style to cause the second automobile icon 112 to move relativeto the first automobile icon 110. The display 102 provides instantfeedback as to how the driver is performing with respect to the chosenenergy performance measure. The display may encourage a driver to modifytheir driving style to attempt to “catch” up with the target automobileicon 110. The driver may be motivated to match performance of thetarget.

FIG. 3 depicts a flowchart that may be implemented in a controller 104.Operation 200 may display the range of values appropriate for the chosenenergy consumption measure. Operation 202 may calculate the targetenergy consumption rate. The target energy consumption rate may bestored in a table within the controller. Operation 204 may calculate thetarget energy consumption value based on the target energy consumptionrate. Operation 206 may cause an icon to be displayed for the targetenergy consumption value.

Operation 208 may calculate the instantaneous or present energyconsumption value. The present energy consumption value may depend onthe type of energy consumption measure to be displayed. Operation 210may determine the position at which to display the icon associated withthe present energy consumption value. The position may be relative tothe icon associated with the target energy consumption value. Thedistance between the icons may be based on the difference between thetarget energy consumption value and the present energy consumptionvalue. Operation 212 may cause the icon associated with theinstantaneous energy consumption value to be displayed on the display102. The system is not limited to the particular order of operations asdescribed and different sequencing of the operations is possible.

The processes, methods, or algorithms disclosed herein can bedeliverable to/implemented by a processing device, controller, orcomputer, which can include any existing programmable electronic controlunit or dedicated electronic control unit. Similarly, the processes,methods, or algorithms can be stored as data and instructions executableby a controller or computer in many forms including, but not limited to,information permanently stored on non-writable storage media such as ROMdevices and information alterably stored on writeable storage media suchas floppy disks, magnetic tapes, CDs, RAM devices, and other magneticand optical media. The processes, methods, or algorithms can also beimplemented in a software executable object. Alternatively, theprocesses, methods, or algorithms can be embodied in whole or in partusing suitable hardware components, such as Application SpecificIntegrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs),state machines, controllers or other hardware components or devices, ora combination of hardware, software and firmware components.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms encompassed by the claims.The words used in the specification are words of description rather thanlimitation, and it is understood that various changes can be madewithout departing from the spirit and scope of the disclosure. Aspreviously described, the features of various embodiments can becombined to form further embodiments of the invention that may not beexplicitly described or illustrated. While various embodiments couldhave been described as providing advantages or being preferred overother embodiments or prior art implementations with respect to one ormore desired characteristics, those of ordinary skill in the artrecognize that one or more features or characteristics can becompromised to achieve desired overall system attributes, which dependon the specific application and implementation. These attributes mayinclude, but are not limited to cost, strength, durability, life cyclecost, marketability, appearance, packaging, size, serviceability,weight, manufacturability, ease of assembly, etc. As such, embodimentsdescribed as less desirable than other embodiments or prior artimplementations with respect to one or more characteristics are notoutside the scope of the disclosure and can be desirable for particularapplications.

What is claimed is:
 1. A vehicle comprising: a display; and at least onecontroller programmed to operate the display according to a referenceenergy consumption value that is based on a predetermined target energyconsumption rate and a present energy consumption value such that aposition of a first icon relative to a position of a second icon isbased on a difference between the reference energy consumption value andthe present energy consumption value.
 2. The vehicle of claim 1 whereinthe at least one controller is further programmed to display a firstnumerical value associated with the first icon and a second numericalvalue associated with the second icon, wherein the first numerical valuecorresponds to the reference energy consumption value and the secondnumerical value corresponds to the present energy consumption value. 3.The vehicle of claim 1 wherein the present energy consumption value isbased on a time averaged energy consumption rate.
 4. The vehicle ofclaim 1 wherein the present energy consumption value is based on adistance averaged energy consumption rate.
 5. The vehicle of claim 1wherein the present energy consumption value is based on a distancetraveled during an ignition cycle.
 6. The vehicle of claim 1 wherein thepresent energy consumption value is based on a present amount of energyremaining in a traction battery.
 7. The vehicle of claim 1 wherein thepresent energy consumption is based on an amount of energy that atraction battery is capable of storing at full charge.
 8. The vehicle ofclaim 1 wherein the present energy consumption value is a distanceremaining to fully discharge a traction battery.
 9. The vehicle of claim1 wherein the present energy consumption value is a predicted distancetraveled if a traction battery is fully charged and energy is used at apresent actual energy consumption rate.
 10. A method for displayingvehicle energy consumption on a display comprising: displaying a firsticon associated with a reference energy consumption value that is basedon a predetermined target energy consumption rate; and displaying, at aposition relative to the first icon by a distance that is based on adifference between a present energy consumption value and the referenceenergy consumption value, a second icon associated with the presentenergy consumption value.
 11. The method of claim 10 further comprisingdisplaying a first numerical value associated with the first icon and asecond numerical value associated with the second icon, wherein thefirst numerical value corresponds to the reference energy consumptionvalue and the second numerical value corresponds to the present energyconsumption value.
 12. The method of claim 10 further comprisingdisplaying a scale corresponding to a range of values for energyconsumption, wherein the first icon is positioned adjacent the scale ata position corresponding to the reference energy consumption value andthe second icon is positioned adjacent the scale at a positioncorresponding to the present energy consumption value.
 13. The method ofclaim 10 wherein the present energy consumption value is based on aratio of power supplied by a traction battery to total power supplied bya vehicle.
 14. The method of claim 10 wherein the present energyconsumption value is based on a distance averaged energy consumptionrate.
 15. The method of claim 10 wherein the present energy consumptionvalue is a distance remaining to fully discharge a traction battery. 16.The method of claim 10 wherein the present energy consumption value is apredicted distance traveled if a traction battery is fully charged andenergy is used at a present energy consumption rate.
 17. A vehiclecomprising: a powertrain including a traction battery; a display; and atleast one controller programmed to operate the display to indicate aneffective electric distance traveled that is based on a ratio of powersupplied by the traction battery to total power supplied by thepowertrain.
 18. The vehicle of claim 17 wherein the powertrain includesan internal combustion engine, and wherein total power supplied by thepowertrain includes power supplied by the internal combustion engine.19. The vehicle of claim 17 wherein the at least one controller isfurther programmed to operate the display to indicate a referenceelectric distance traveled that is based on a predetermined targetenergy consumption rate.
 20. The vehicle of claim 19 wherein the atleast one controller is further programmed to operate the display suchthat a position of a first icon, representing the effective electricdistance traveled, relative to a position of a second icon, representingthe reference electric distance traveled, is based on a differencebetween the reference electric distance traveled and the effectiveelectric distance traveled.